Composition in the form of an O/W emulsion with a high wax content, and uses thereof in cosmetics and dermatology

ABSTRACT

A creamy composition in the form of an oil-in-water emulsion comprising an oily phase dispersed in an aqueous phase, characterized in that it contains at least one anionic emulsifier which is liquid at room temperature, and at least 5% by weight of one or more waxes relative to the total weight of the composition, and in that the oily phase is in the form of a soft paste at room temperature. The anionic emulsifier is preferably a surfactant containing a phosphate group, such as octyldecyl phosphate. 
     The present invention also relates to the uses of the said composition in cosmetics and dermatology, in particular for caring for, treating and/or making up the skin and/or mucous membranes, and more particularly for treating wrinkles and/or fine lines of the skin and/or for treating dry skin. 
     The invention also relates to a process for preparing this composition, characterized in that at least one step of the process is carried out using a mixer-extruder.

This application is a Continuation of application Ser. No. 09/451,918,filed Dec. 1, 1999, now U.S. Pat. No. 6,264,965.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a composition in the form of anoil-in-water (O/W) emulsion comprising a high content of wax, and to itsuses in cosmetics and dermatology, in particular for caring for,treating and/or making up the skin and/or mucous membranes, and moreparticularly for treating wrinkles and/or fine lines of the skin and/orfor treating and/or protecting dry skin. The invention also relates to aprocess for preparing this composition, where at least one step of theprocess is carried out using a mixer-extruder.

2. Description of the Invention

It is well-known to use waxes in cosmetic creams in the form ofemulsions intended for caring for human skin, in particular for theanti-wrinkle effects provided by these waxes. However, it is difficultto incorporate a high percentage of waxes into these compositions sincewaxes have a tendency to thicken the emulsions considerably. Inaddition, when a high percentage of waxes is incorporated into anemulsion, the emulsion is very difficult to apply to the skin since itdoes not slide. Moreover, a coarse effect appears on the skin. Such anemulsion is therefore unacceptable to users.

Furthermore, it is known to incorporate a high percentage of waxes intomascaras. However, compositions of this type cannot be used as careproducts on account of the drawbacks mentioned above.

Moreover, to prepare an emulsion containing waxes, it is necessary tomelt the waxes in the fatty phase of the emulsion, in particular if itis desired, for example, to use waxes such as carnauba waxes which areparticularly advantageous for their anti-wrinkle effect on the skin. Itis thus necessary to heat the fatty phase up to 80-85° C., which isparticularly harmful when it is desired to introduce heat-sensitivecompounds.

Therefore, a need exists for a composition containing a high percentageof waxes which is free of the drawbacks of the compositions describedabove.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an oil-in-wateremulsion that contains wax.

It is another object of the present invention to provide methods oftreating skin, especially human skin, using the oil-in-water emulsionthat contains wax.

The inventors having discovered, surprisingly, that a high percentage ofwaxes can be incorporated into O/W emulsions while at the same timeretaining satisfactory fluidity and a pleasant sensation when it isapplied to the skin, by preparing the emulsion without heating, using ananionic emulsifier which is liquid at room temperature and starting witha soft oily phase containing a high percentage of waxes.

Accordingly, the objects of the invention, and others, maybeaccomplished with a creamy composition in the form of an oil-in-wateremulsion and comprising:

an oily phase dispersed in an aqueous phase,

at least one anionic emulsifier which is a liquid at room temperature,and

at least 5% by weight, relative to the total weight of the composition,of at least one wax,

where the oily phase is in the form of a soft paste at room temperature.

The objects of the present invention may also be accomplished with amethod of treating wrinkles and/or fine lines of the skin, comprisingapplying an effective amount of the inventive composition to the skin.

The objects of the present invention may also be accomplished with amethod of treating and/or protecting dry skin, comprising applying theeffective amount of the inventive composition to the skin.

The objects of the present invention may also be accomplished with amethod of preparing the inventive composition, comprising dispersing theoily phase in the aqueous phase.

The objects of the present invention may also be accomplished with amethod of preparing the inventive composition, comprising:

(a) preparing the oily phase in the form of a soft paste by mixing thewaxes and oils,

(b) heating the oily phase to a temperature at which it melts,

(c) introducing melted oily phase and the other constituents of the oilyphase into a mixer-screw extruder subjected to a temperature gradientranging from 80° C. to 20° C.,

(d) blending the mixture obtained while at the same time cooling it toroom, temperature while it is conveyed to the outlet of themixer-extruder to produce a soft paste,

(e) incorporating the emulsifier and, optionally, if present, theco-emulsifier into the soft paste obtained from (d), and

(f) incorporating the mixture from (e) into the aqueous phase.

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description.

DETAILED DESCRIPTION OF THE INVENTION

The composition of the present invention is in the form of a cream, i.e.a soft product, as opposed to the solid structure of a stick. A creamhas a viscosity at room temperature (about 20-25° C.) between 1 to 10Pa.s, measured with a Rheomat 180. This range includes all specificvalues and subranges therebetween, such as 2, 3, 5 and 8 Pa.s.

Although containing a large amount of wax, the composition obtainedfeels fresh when applied.

The anionic emulsifier used in the composition of the invention isliquid at room temperature, i.e. at a temperature ranging from 15° C. to25° C. It can be chosen in particular from the group of anionicsurfactants containing a phosphate group, which are liquid at roomtemperature, such as mono-, di- and/or triesters of phosphoric acid andof a C₁₂ to C₂₂ fatty alcohol, i.e. of an alcohol having an alkyl chaincontaining from 12 to 22 carbon atoms (inclusive of all specific valuesand subranges therebetween, such as 14, 16, 18 and 20 carbon atoms), andmono-, di- and/or triesters of phosphoric acid and of an ethoxylatedfatty alcohol, having a fatty chain containing from 12 to 22 carbonatoms (inclusive of all specific values and subranges therebetween, suchas 14, 16 from 20 carbon atoms) and a number of ethoxylated unitsranging from 1 to 100 and preferably from 4 to 25 (inclusive of allspecific values and subranges therebetween, such as 2, 5, 10, 15, 35,50, 75 and 90).

Anionic emulsifiers that are liquid at room temperature which arepreferred are oleyl phosphate (mixture of mono- and diester ofphosphoric acid and of oleyl alcohol), trioleyl phosphate, dilaureth-4phosphate (mixture of diesters of phosphoric acid and of polyethyleneglycol ether and of lauryl alcohol, containing 4 oxyethylenated groups),trioleth-8 phosphate (mixture of triesters of phosphoric acid and ofether of polyethylene glycol and of oleyl alcohol, containing 8oxyethylenated groups), triceteareth-4 phosphate (mixture of triestersof phosphoric acid and of ether of polyethylene glycol and of cetyl andstearyl alcohols, containing 4 oxyethylenated groups), the monoester ofphosphoric acid and of stearic and isostearic acid (CTFA name:octyldecyl phosphate) sold under the name Hostaphat CG 120 by Clariant,and mixtures thereof. According to one preferred embodiment of theinvention, octyldecyl phosphate is used.

The amount of emulsifier in the composition according to the inventiongenerally ranges from 0.1 to 10% by weight of active material andpreferably from 1 to 5% by weight of active material relative to thetotal weight of the composition. These ranges includes all specificvalues and subranges therebetween, such as 0.2, 0.5, 2, 3, and 8% byweight.

A co-emulsifier can optionally be added to the anionic emulsifier whichis liquid at room temperature, provided that the mixture of theemulsifier and the co-emulsifier is liquid at room temperature.

Co-emulsifiers which may be used include, for example, fatty alcoholscomprising a branched or unsaturated chain containing from 8 to 22carbon atoms (inclusive of all specific values and subrangestherebetween, such as 10, 12, 14, 16, 18 and 20 carbon atoms), such asisostearyl alcohol, fatty acids comprising a branched or unsaturatedchain containing from 8 to 22 carbon atoms (inclusive of all specificvalues and subranges therebetween such as 10, 12, 14, 16, 18 and 20carbon atoms), such as ricinoleic acid, and mixtures thereof.

When the composition contains a coemulsifier, the amount ofco-emulsifier generally ranges from 0.1 to 10% by weight of activematerial and preferably from 1 to 5% by weight of active materialrelative to the total weight of the composition. These ranges includesall specific values and subranges therebetween, such as 0.2, 0.5, 2, 3,and 8% by weight.

The composition of the invention contains, in the oily phase, at least5% by weight of one or more waxes relative to the total weight of thecomposition. The oily phase, cooled before it is mixed with the aqueousphase, is advantageously in the form of a soft paste at room temperature(about 25° C). The expression “soft paste” as used herein refers to apaste whose viscosity can be measured, as opposed to the solid structureof a tube or stick, whose viscosity cannot be measured. The dynamicviscosity of the soft paste at 25° C. is generally between 3 and 35Pa.s, measured with a Contraves TV rotary viscometer fitted with anMS-r4 rotor at a frequency of 60 Hz. This range includes all specificvalues and subranges therebetween such as 5, 10, 15, 20, 25 and 30 Pa.s.

The fact that the oily phase is in the form of a soft paste at roomtemperature allows to prepare the emulsion (mixing of the oily andaqueous phases) without heating and to obtain a creamy composition whichis easy to apply on the skin and pleasant to use, and this in spite of alarge amount of waxes.

Examples of waxes which can be used in the composition of the inventioninclude, for example, of mineral waxes such as microcrystalline waxes,paraffin, petrolatum, petroleum jelly, ozokerite, montan wax; animalwaxes such as beeswax, lanolin and its derivatives; plant waxes such ascandelilla wax, ouricury wax, carnauba wax, Japan wax, cocobutter, corkfibre wax or sugar cane wax; hydrogenated oils; fatty esters andglycerides which are solid at 25° C.; synthetic waxes such aspolyethylene waxes and the waxes obtained by Fischer-Tropsch synthesis;silicone waxes, and mixtures thereof.

According to one preferred embodiment of the invention, at least one waxhaving a starting melting point of greater than or equal to 50° C., andbetter still at least one wax whose starting melting point is greaterthan 65° C., is used, such as carnauba wax, certain polyethylene waxesand certain microcrystalline waxes such as the one sold by Tisco as“Tisco Wax 88” or the one sold by RMC as “Feruwax 30540”.

As used herein, the term “starting melting point” means the temperatureat which a wax begins to melt. This temperature can be determined by DTA(differential thermal analysis), which allows the production of athermogram (or melting curve) of the wax under consideration. Thestarting melting point corresponds to the temperature at which anappreciable change in the slope of the thermogram can be observed. Themelting point itself represents the minimum point of the saidthermogram.

The amount of wax(es) in the composition of the invention is at least 5%and preferably ranges from 5 to 30%, and better still from 5 to 15%, byweight relative to the total weight of the composition. These rangesincludes all specific values and subranges therebetween, such as 10, 12,18, 20 and 25% by weight.

The amount of oily phase in the composition of the invention generallyranges from 10 to 70% and preferably from 20 to 50% by weight relativeto the total weight of the composition. These ranges includes allspecific values and subranges therebetween, such as 15, 25, 30, 40 and60% by weight. This oily phase is used in an amount such that, or elsecontains an amount of waxes such that, the amount of waxes in the finalcomposition is greater than or equal to 5%.

The oily phase of the composition of the invention generally comprises,besides the wax(es), one or more fatty substances chosen from oils ofanimal origin, oils of plant origin, mineral oils, synthetic oils,fluoro oils, silicone oils and in particular volatile silicone oils,silicone gums, silicone resins, fatty alcohols, fatty acids and siliconeelastomers such as the products sold as “KSG” by Shin-Etsu, as “Trefil”by Dow Corning or as “Gransil” by General Electric.

Preferably, the composition of the invention can also contain one ormore fillers (pulverulent constituents) which can be chosen, forexample, from the group formed by talc; micas of natural or syntheticorigin; kaolin; zinc oxide or titanium oxide; calcium carbonate;magnesium carbonate and hydrocarbonate; silica, in particular sphericalsilica, the silica powder sold as “Cab-O-Sil TS 530” by Cabot, andsilica microbeads such as those sold as SB150 by Myoshi; titaniumdioxide; glass beads and ceramic beads sold by 3M under the trade name“Macrolite”; metal soaps derived from organic carboxylic acidscontaining from 8 to 22 carbon atoms, preferably from 12 to 18 carbonatoms, for example zinc, magnesium or lithium stearate, zinc laurate,magnesium myristate; non-expanded synthetic polymer powders, such aspowders of polyethylene, of polystyrene, of polyesters, of polyamides(for example Nylon or poly-β-alanine), of acrylate copolymers (forexample the microporous microspheres sold by Dow Corning under the tradename “Polytrap”), of polymethacrylic acids, of polystyrene or of Teflon,such as “Fluon”; expanded powders such as hollow microspheres made of athermoplastic material, prepared by known processes, for example thosedescribed in U.S. Pat. No. 3,615,972, incorporated herein by reference,and EP-A-056,219, incorporated herein by reference, and in particularthe microspheres sold as “Expancel” by Kemanord Plast or as “MicropearlF 80 ED” by Matsumoto; powders of natural organic materials such ascrosslinked or non-crosslinked corn, wheat or rice starch, such as thepowders of starch crosslinked with octenyl succinic anhydride which aresold as “Dry-Flo” by National Starch; silicone resin microbeads, such asthose sold as “Tospearl” by Toshiba Silicone, and mixtures thereof.

The fillers can represent up to 20% by weight relative to the totalweight of the composition, and preferably from 1 to 12% by weightrelative to the total weight of the composition. These ranges includesall specific values and subranges therebetween, such as 0.1, 0.2, 0.5,2, 3, 5, 8, 10 and 15% by weight.

The aqueous phase of the composition of the invention represents atleast 30% by weight and preferably from 50 to 80% by weight relative tothe total weight of the composition. These ranges includes all specificvalues and subranges therebetween, such as 35, 40, 45, 60, 70, and 75%by weight.

The composition according to the invention can be used in any field inwhich this type of pharmaceutical form is advantageous, and inparticular in cosmetics and dermatology. When it constitutes a cosmeticand/or dermatological composition, it advantageously contains aphysiologically acceptable medium, i.e. a medium which is compatiblewith the skin, mucous membranes, the nails and/or the hair.

The compositions which are the subject of the invention can be appliedto a large number of treatments of the skin, mucous membranes (lips) andthe hair, including the scalp, in particular for protecting, caring for,cleansing and/or making up the skin and/or mucous membranes, forprotecting, caring for and/or cleansing the hair and/or fortherapeutically treating the skin, the hair and/or mucous membranes.

The compositions according to the invention can be used, for example, astreatment, care, protection and/or cleansing products for the skin inthe form of creams or milks, or as make-up products (for the skin andlips) by incorporation of fillers and/or dyestuffs (pigments and/ordyes). They are particularly suitable for treating wrinkles and/or finelines of the skin and for treating and/or protecting dry skin.

Thus, the present invention also includes the cosmetic use of thecomposition as defined above for treating, protecting, caring for and/orcleansing the skin, mucous membranes and/or the hair, and/or for makingup the skin and/or mucous membranes.

The present invention also includes the cosmetic use of the compositionas defined above for treating wrinkles and/or fine lines of the skin.

The present invention also includes the use of the composition asdefined above for the manufacture of a composition intended for treatingand/or protecting dry skin.

In addition, as is well-known, the compositions of the invention cancontain adjuvants that are common in cosmetics or dermatology, such ashydrophilic or lipophilic active agents, preserving agents,antioxidants, fragrances, solvents, sunscreens, dyestuffs, basic oracidic agents and lipid vesicles. These adjuvants are used in the usualproportions in cosmetics or dermatology, and, for example, from 0.01 to30% of the total weight of the composition, and, depending on theirnature, they are introduced into the aqueous phase or into the oilyphase of the composition, or alternatively into vesicles. Theseadjuvants, and their concentrations, should be such that they do notmodify the property which is desired for the composition.

If it is desired to obtain a less fluid composition and/or to improvethe stability of the emulsion, one or more hydrophilic gelling agentssuch as carboxyvinyl polymers or carbomers and polyacrylamides can beadded thereto. These gelling agents are used at concentrations generallyranging from 0.05 to 2%, preferably 0.1 to 0.5%, by weight relative tothe total weight of the composition.

As active agents which can be used in the composition of the invention,mention may be made, for example, of moisturizers such as polyols and inparticular glycerol, ethylene glycol, isoprene glycol, 1,2-propanediol,diglycerol, sorbitol, polyethylene glycols and mixtures thereof.

The composition according to the invention can be advantageouslyprepared using, for at least one step of the process, a blending machinesuch as a roll mill comprising two rollers rotating in oppositedirections, between which the paste passes, or a mixer-screw extruder. Amixer-screw extruder is preferably used.

Another aspect of the invention is thus a process for preparing acomposition according to the invention, characterized in that at leastone step of the process is carried out using a mixer-screw extruder.

According to a first embodiment of the invention, the preparationprocess comprises the following steps:

(1) preparation of the oily phase in the form of a soft paste obtainedby preparing a premix of the waxes and oils, heating this premix to atemperature at which it melts and then introducing the molten premix andthe other constituents (in particular the fillers) of the oily phaseinto a mixer-screw extruder subjected to a temperature gradient rangingfrom 80° C. to 20° C., in one or more portions, and blending the mixtureobtained while at the same time cooling it to room temperature while itis conveyed to the outlet of the mixer-extruder;

(2) incorporation of the emulsifier and optionally the co-emulsifierinto the soft paste obtained in (1), and

(3) incorporation, with stirring, of the mixture obtained in (2) intothe aqueous phase.

In this embodiment, steps (2) and (3) are carried out in a mixingmachine usually used by a person skilled in the art, such as arotor-stator.

In addition, in the process described above, the emulsifier used is ananionic emulsifier which is liquid at room temperature and the amountsused are such that the emulsion obtained comprises at least 5% of wax byweight relative to the total weight of the composition.

As indicated above, since the mixing of the oily and aqueous phases iscarried out without heating, the incorporation of heat-sensitivecompounds poses no problem.

According to one particular embodiment of the invention, steps (2) and(3) above are also carried out in the mixer-screw extruder used for step(1). The emulsifier and the aqueous phase are then introduced into asection (or element) of the mixer-extruder in which the temperature isclose to room temperature.

The use of a mixer-extruder makes it possible to reproducibly obtain apaste of oily phase of very constant quality. Furthermore, it ispossible, by adapting the outlet die of the mixer-extruder, to packagethe composition in-line at the outlet of the said mixer-extruder.

The various steps of the process can be carried out in one or moreextruders arranged one after the other, and preferably in a singletwin-screw extruder.

The conditions under which the extrusion can be carried out aredescribed in document FR-A-2,715,306, incorporated herein by reference.

Having generally described this invention, a further understanding canbe obtained by reference to certain specific examples which are providedherein for purposes of illustration only and are not intended to belimiting unless otherwise specified.

EXAMPLES Example: Care Cream

Oily phase Dry-Flo (filler) 15% Microcrystalline wax 19% Mineral oil qs100% O/W emulsion Oily phase 20% Hostaphat CG 120 (emulsifier) 3%Carbomer 0.2% Water qs 100%

Procedure 1:

The mixture of wax and oil is heated to about 100° C.,

the molten mixture is introduced into a mixer-extruder at the same timeas the filler, and the oily phase is obtained at the mixer-extruderoutlet in the form of a soft paste,

the emulsifier is incorporated into the soft paste in a rotor-stator,

next, the mixture obtained is incorporated portionwise into the aqueousphase (water and carbomer) with stirring.

Procedure 2:

The mixture of wax and oil is heated to about 100° C.,

the filler is introduced into the top element of a mixer-extrudercomprising at least six elements,

the oily phase is introduced into the second element of the saidmixer-screw extruder, and

the aqueous phase and the emulsifier are introduced, via two differentinlets, into the fourth element of the said mixer-screw extruder.

The elements of the mixer-screw extruder used are, going from the firstto the sixth element, maintained at the following respectivetemperatures: 20° C., 80° C., 60° C., 20° C., 20° C. and 20° C.

A cream which has a very light texture and good moisturizing propertiesand which is capable of smoothing out the skin's relief is obtained.

Obviously, additional modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

This application is based on French Patent Application Serial No.98-15293, filed on Dec. 3, 1998, and incorporated herein by reference inits entirety.

What is claimed is:
 1. A creamy composition in the form of anoil-in-water emulsion and comprising: an oily phase dispersed in anaqueous phase, at least one anionic emulsifier which is a liquid at roomtemperature, and at least 5% by weight, relative to the total weight ofthe composition, of at least one wax, wherein the oil phase is in theform of a soft paste which has a dynamic viscosity at 25° C. of between3 and 35 Pa.s as measured with a Contraves TV rotary viscometer fittedwith an MS-r4 rotor at a frequency of 60 Hz.
 2. The composition of claim1, wherein the anionic emulsifier is selected from the group consistingof anionic surfactants containing a phosphate group.
 3. The compositionof claim 1, wherein the emulsifier is selected from the group consistingof mono-, di- and/or triesters of phosphoric acid and of a fatty alcoholhaving a fatty chain containing from 12 to 22 carbon atoms, and mono-,di- and/or triesters of phosphoric acid and of an ethoxylated fattyalcohol, having a fatty chain containing from 12 to 22 carbon atoms anda number of ethoxylated units ranging from 1 to
 100. 4. The compositionof claim 1, wherein the emulsifier is selected from the group consistingof oleyl phosphate, trioleyl phosphate, dilaureth-4 phosphate,trioleth-8 phosphate, triceteareth-4 phosphate, the monoester ofphosphoric acid and of stearic and isostearic acid, and mixturesthereof.
 5. The composition of claim 1, wherein the amount of emulsifierranges from 0.1 to 10% by weight of active material relative to thetotal weight of the composition.
 6. The composition of claim 1, whereinthe composition further comprises a co-emulsifier.
 7. The composition ofclaim 6, wherein the co-emulsifier is selected from the group consistingof fatty alcohols containing a branched or unsaturated chain containingfrom 8 to 22 carbon atoms, fatty acids containing a branched orunsaturated chain containing from 8 to 22 carbon atoms, and mixturesthereof.
 8. The composition of claim 6, wherein the amount ofco-emulsifier ranges from 0.1 to 10% by weight of active materialrelative to the total weight of the composition.
 9. The composition ofclaim 1, wherein the wax is selected from the group consisting ofmineral waxes, animal waxes, plant waxes, hydrogenated oils, fattyesters and glycerides which are solid at 25° C., synthetic waxes,silicone waxes, and mixtures thereof.
 10. The composition of claim 1,comprising at least one wax having a starting melting point of greaterthan or equal to 50° C.
 11. The composition of claim 1, wherein the waxis chosen from carnauba wax, polyethylene waxes with a starting meltingpoint of greater than 65° C., microcrystalline waxes with a startingmelting point of greater than 65° C., and mixtures thereof.
 12. Thecomposition of claim 1, wherein the amount of wax ranges from 5 to 30%by weight relative to the total weight of the composition.
 13. Thecomposition of claim 1, wherein the amount of oily phase ranges from 10to 70% by weight relative to the total weight of the composition. 14.The composition of claim 1, wherein the oily phase also comprises one ormore fatty substances selected from the group consisting of oils ofanimal origin, oils of plant origin, mineral oils, synthetic oils,fluoro oils, silicone oils, volatile silicone oils, silicone gums,silicone resins, fatty alcohols, fatty acids and silicone elastomers.15. The composition of claim 1, wherein it also comprises at least onefiller.
 16. The composition of claim 15, wherein the amount of fillerranges from 1 to 12% by weight relative to the total weight of thecomposition.
 17. The composition of claim 1, wherein the aqueous phaserepresents from 50 to 80% by weight relative to the total weight of thecomposition.
 18. The composition of claim 1, which is a cosmetic and/ordermatological composition.
 19. The cosmetic of claim 1, which issuitable for treating, protecting, caring for and/or cleansing the skin,mucous membranes and/or the hair, and/or for making up the skin and/ormucous membranes.
 20. A method of treating wrinkles and/or fine lines ofthe skin, comprising applying an effective amount of the composition ofclaim 1 to the skin.
 21. A method of treating and/or protecting dryskin, comprising applying the effective amount of the composition ofclaim 1 to the skin.
 22. A method of preparing the composition of claim1, comprising dispersing the oily phase in the aqueous phase.
 23. Themethod of claim 22, wherein at least one step of the method is conductedin a mixer-screw extruder.
 24. The composition of claim 1, wherein theroom temperature ranges from 15° C. to 25° C.
 25. The composition ofclaim 1, wherein the room temperature is about 20-25° C.
 26. Thecomposition of claim 1, wherein the room temperature is about 25° C. 27.The composition of claim 1, wherein said soft paste has a viscosity thatcan be measured.
 28. A creamy composition in the form of an oil-in-wateremulsion and comprising: an oily phase dispersed in an aqueous phase, atleast one anionic emulsifier which is a liquid at room temperature, andat least 5% by weight, relative to the total weight of the composition,of at least one wax, wherein the oily phase is in the form of a softpaste at room temperature; and wherein said composition is prepared by aprocess comprising: (a) preparing the oily phase in the form of a softpaste by mixing the waxes and oils; (b) heating the oily phase to atemperature at which it melts; (c) introducing melted oily phase and theother constituents of the oily phase into a mixer-screw extrudersubjected to a temperature gradient ranging from 80° C. to 20° C.; (d)blending the mixture obtained while it is conveyed to the outlet of themixer-screw extruder to produce a soft paste; (e) incorporating theemulsifier and, optionally, if present the co-emulsifier into the softpaste obtained from (d), and (f) incorporating the mixture from (e) intothe aqueous phase; to thereby obtain said composition.